How to change the default combination in a certain category in Prestashop?

Question

Prestashop

How to change the default combination in a certain category in Prestashop?
Website Arthata.by

The essence of the problem and question:
There is a product with combinations of goods. I want to assign multiple product categories to this products. And based on the category, the desired combination should be selected when opening a product in this category or when viewing a product in this category.

I googled these lines of code, but I do not understand how to use:

public function setWsDefaultCombination($id_combination)
    {
        $this->deleteDefaultAttributes();
        return $this->setDefaultAttribute((int) $id_combination);
    }

I'm thinking of doing this code:

if ($category->id == "21")
{$this->setDefaultAttribute(55);}

The code is not quite correct, but I think this is the direction.
The question is where to insert, and how to correct?
Help....